G. Carl Huber 399 
nized in the boundary zone and medulla as arteriole rectee vere and in 
the peripheral portion of the cortex as end branches of the interlobular 
arteries. The criticism may be made that the corrosion method em- 
ployed is not suitable for determining the existence or non-existence of 
such branches, as the possibility of their being present without being 
injected must be considered. It would seem, however, reasonable to sup- 
pose that arteriole recte vere should be more readily injected than 
arteriole rect spurie, since in injecting the former it would not be 
necessary for the injection mass to pass through the glomerular capillaries 
before reaching the branches and capillaries constituting the arteriole 
recta. The ven recte are very readily injected through the veins. In 
the rat, guinea pig, and rabbit and practically without exception in the 
cat, the arteriole rectee observed in my corrosions could readily be traced 
to the efferent glomerular vessels. In these forms then, the existence of 
arteriole rectee vere may be denied with the possibility of very rare ex- 
ceptions in the cat. A similar conclusion is reached by Petraroja, whose 
account I have, however, seen only in review, as his original publi- 
cation was inaccessible to me.” In the dog, I have now and then observed 
arterial twigs which terminate directly in arteriole rectee—arteriole rect 
veree—these constitute, however, a very small per cent, the great majority 
resulting from a division of efferent glomerular branches. In the dog 
there may be further observed what may be designated as very small glom- 
eruli, which appear fully injected as a capillary network may generally 
be made out in the corrosion, the efferent branch ending in typical 
arteriole rectee. These very small glomeruli (?) are also not numerous. 
Golubew has described and figured for the dog and the cat what he has 
termed “ retia mirabilia renum nova” situated in the deeper portion of 
the cortical substance and the boundary zone. Being aware of these ob- 
servations of Golubew, I sought for confirmation of them in the corrosion — 
preparations at my disposal, as it seemed likely that they should be in- 
jected as readily as the glomerular vessels. Such retia mirabilia have 
not been found, unless, as seems to me probable, what has been spoken of 
as very small glomeruli may constitute the structure described by Golubew 
as new renal retia mirabilia. From the fact that the efferent vessels of 
such structures always end, so far as I have been able to determine, in 
arteriole recta, I have been led to conclude that they represent the re- 
mains of normal glomeruli associated in their development with urinifer- 
®°Petraroja: Sulle arteriole recte del rene. Monit. Zool. ital., Bd. 15, 1904. 
Reviewed in Jahresberichte tiber die Fortschritte der Anatomie und Ent- 
wickelungsgeschichte. Neue Folge, Bd. X, 3 Abth. 1. Teil, 1905. 
